JP6311459B2 - Tip-worked steel sheet pile and its placing method - Google Patents

Description

  The present invention relates to a tip processed steel sheet pile in which a predetermined processing is applied to a tip end portion of a steel sheet pile, and a driving method thereof.

  Conventionally, it is disclosed in Patent Document 1 that the deformation and damage at the time of placing can be suppressed and a high vertical support force can be reliably exhibited and an inexpensive foundation structure can be constructed. Steel sheet piles have been proposed.

  The steel sheet pile disclosed in Patent Document 1 is a steel sheet pile placed on the ground by joining a closed steel material to the tip of the steel sheet pile body, closing the open section of the steel sheet pile body to a closed section shape. At that time, the lump that has entered the closed cross-section portion is compacted to close the tip portion of the steel sheet pile main body, and a high tip support force can be obtained.

JP 2008-248503 A

  However, in the steel sheet pile disclosed in Patent Document 1, when placing the steel sheet pile on the ground, an intermediate layer such as a soft ground that the tip of the steel sheet pile main body is propelled, or the tip of the steel sheet pile main body There is no disclosure of a placement method for smoothly placing a steel sheet pile with a support layer that reaches the bottom.

  For this reason, in the steel sheet pile disclosed in Patent Document 1, since the closed steel material is joined at the tip of the steel sheet pile main body to form a closed cross-sectional shape, the earth lump entering the closed cross-section portion is compacted and the steel sheet pile main body On the other hand, the tip of the steel sheet pile body may be difficult to propel with an intermediate layer such as soft ground. there were.

  Therefore, the present invention has been devised in view of the above-described problems, and its object is to smoothly promote the steel sheet pile main body in the ground when placing the steel sheet pile on the ground. It is another object of the present invention to provide a tip-worked steel sheet pile capable of accurately propelling the steel sheet pile main body by moving substantially straight, and a method for placing the same.

A tip processed steel sheet pile according to a first aspect of the present invention is a tip processed steel sheet pile in which a predetermined processing is applied to a tip portion of a steel sheet pile, and a pair of flanges formed continuously at both ends of a web portion and the web portion. A steel sheet pile main body having a portion, and a closed steel material provided at a distal end portion of the steel sheet pile main body in the longitudinal direction, the steel sheet pile main body having an open cross section formed by the web portion and the pair of flange portions. The closed steel material is joined so as to be closed, and a tip processing portion is formed at a tip portion in the longitudinal direction. The tip processing portion is a cross-sectional view with respect to the longitudinal direction of the steel sheet pile main body, and the steel sheet pile The main body side on which the steel sheet pile main body is provided substantially point-symmetrically with respect to the center point of the closed cross section formed by the main body and the closed steel material and with respect to the joining line between the steel sheet pile main body and the closed steel material And the closed steel material is provided. As a non-axisymmetric with the working side that is characterized by water jet tube is mounted.

Tip Processed steel sheet pile according to the second invention, Oite the first shot bright, the tip machining portion, and quantity of the water jet tube which is mounted on the main body side, the water jet mounted in the machining side and quantity of the tube, characterized in that in which the same.

A tip-working steel sheet pile driving method according to the third invention is a tip-working steel sheet pile driving method in which a predetermined processing is applied to the tip portion of the steel sheet pile, and has a web portion and a pair of flange portions. A propulsion step of propelling a processed steel sheet pile having a sheet pile main body and a closed steel material joined to a longitudinal tip portion of the steel sheet pile main body in the ground, and in the propulsion step, the steel sheet pile main body is grounded The steel sheet pile main body is provided as a substantially straight traveling body , and the steel sheet pile main body is joined to the closed steel material so as to close an open cross section formed by the web portion and the pair of flange portions, A tip processing portion is formed at a tip portion in the longitudinal direction, and the tip processing portion is a closed section formed by the steel sheet pile main body and the closed steel material in a cross-sectional view with respect to the longitudinal direction of the steel sheet pile main body. Paired with the center point of the section Substantially point-symmetric and non-axisymmetric between the main body side where the steel sheet pile main body is provided and the processing side where the closed steel material is provided with respect to the joining line between the steel sheet pile main body and the closed steel material. As described above, a water jet pipe is mounted .

According to the 1st invention-the 3rd invention, in the main body side in which the steel sheet pile main body is provided, and the processing side in which the closed steel material is provided, the jet pressure of the water jet pipe is balanced, so As a result, it becomes possible to smoothly propel the tip processing portion, and at the same time, it is possible to accurately propel the steel sheet pile main body substantially straightly in the ground.

According to the first to third inventions, for example, by limiting the number of water jet tubes mounted on the tip processing portion to two, the increase in the number of water jet tubes is suppressed, and the water jet It becomes possible to reduce the material cost and installation cost of the pipe. Moreover, according to the 1st invention- the 3rd invention, the steel sheet pile main body is inclined in the ground by balancing the jetting pressure in the cross sectional direction from the water jet pipe in the cross sectional view with respect to the longitudinal direction of the steel sheet pile main body. Without any problem, the steel sheet pile main body can be accurately moved straight.

It is a perspective view which shows the front-end | tip processed steel sheet pile to which this invention is applied. (A) is a top view which shows 1st Example of the front-end | tip processed steel sheet pile to which this invention is applied, (b) is the front view. (A) is a top view which shows 2nd Example of the tip process steel sheet pile to which this invention is applied, (b) is the front view. (A) is a side view which shows the front-end | tip processed steel sheet pile to which this invention is applied, (b) is the EE line arrow cross-sectional view, (c) is the FF line arrow. FIG. It is an expanded cross-sectional view which shows the front end process part of the front end process steel sheet pile to which this invention is applied. It is a side view which shows the state by which the front end process part of a front end process steel sheet pile is embedded from the surface layer of a ground by the propulsion process in the placement method of the front end process steel sheet pile to which this invention is applied. It is a side view which shows the state which the steel sheet pile main body of a tip-worked steel sheet pile advances substantially straight in the intermediate | middle layer in a ground at the propulsion process in the placement method of the tip-worked steel sheet pile to which this invention is applied. It is a side view which shows the state which stopped the ejection of the high pressure water from the nozzle of a water jet pipe | tube in the propulsion process in the placement method of the tip-worked steel sheet pile to which this invention is applied. (A) is an expanded side view which shows the front-end | tip processed part of the front-end | tip processed steel sheet pile to which this invention is applied, (b) is an expanded cross-sectional view which shows the state where the earth and sand which entered the closed cross section were compacted It is. It is a side view which shows the state which made the front end process part of the front end process steel sheet pile reach the support layer in the ground at the support process in the placement method of the front end process steel sheet pile to which this invention is applied. (A) is a side view which shows the state in which the tip-worked steel sheet pile to which this invention is applied advances substantially straight in the ground, and (b) is a side view showing a state in which a conventional steel sheet pile is inclined in the ground. is there. It is an expanded cross-sectional view which shows the state which balanced the jet pressure of the cross-sectional direction from a water jet pipe | tube in the front-end | tip processed part of the front-end | tip processed steel sheet pile to which this invention is applied.

  Hereinafter, a form for carrying out tip processed steel sheet pile 1 to which the present invention is applied will be described in detail with reference to the drawings.

  As shown in FIG. 1, the tip-worked steel sheet pile 1 to which the present invention is applied is one in which predetermined processing is applied to the tip portion 2 a of the steel sheet pile main body 2 in order to exert a high tip support force in the ground. Yes, the steel sheet pile main body 2 is driven and embedded in the ground 8 by a method such as striking, vibration or press-fitting.

  As shown in FIG. 2 and FIG. 3, the tip processed steel sheet pile 1 to which the present invention is applied is a steel sheet pile main body 2 formed to have a predetermined cross-sectional shape in the cross-sectional direction X, and the longitudinal direction of the steel sheet pile main body 2. And a closed steel material 3 provided to be joined to the Y tip 2a. As the steel sheet pile main body 2, a hat-shaped steel sheet pile, a U-shaped steel sheet pile, a Z-shaped steel sheet pile, and the like are used, and the closed steel material 3 has a cross-sectional direction X that is substantially the same as the steel sheet pile main body 2, and a longitudinal direction Y The extension of the steel sheet pile body 2 is made shorter than the extension of the steel sheet pile main body 2.

  As shown in FIG. 2, the steel sheet pile main body 2 is a hat-shaped steel sheet pile having a substantially hat-shaped cross section as shown in FIG. 2. The steel sheet pile main body 2 includes a web portion 21, a pair of flange portions 22, and a pair of arm portions 23. The steel sheet pile main body 2 is formed such that a pair of flange portions 22 are continuously inclined at both ends of the web portion 21, and a pair of arm portions 23 are continuous with one end of each of the pair of flange portions 22. Are formed so as to be substantially parallel to the web portion 21. Here, the steel sheet pile main body 2 has a joint portion 24 formed at the tip of each arm portion 23.

  In the first embodiment, the closed steel material 3 is formed to have a substantially hat-shaped cross-sectional shape. The closed steel material 3 is formed by performing a cutting process or the like on a hat-shaped steel sheet pile, and has a closed web portion 31, a pair of closed flange portions 32, and a pair of closed arm portions 33. The closed steel material 3 is formed such that a pair of closing flange portions 32 are continuously inclined at both ends of the closing web portion 31, and a pair of closing arm portions 33 is provided at one end of each of the pair of closing flange portions 32. It is formed continuously. The closed steel material 3 is joined to the distal end portion 2a of the steel sheet pile main body 2 by bringing the respective closed arm portions 33 and the respective arm portions 23 of the steel sheet pile main body 2 into contact with each other and performing welding joint or the like. .

  In the second embodiment, the steel sheet pile main body 2 is a U-shaped steel sheet pile having a substantially U-shaped cross section as shown in FIG. The steel sheet pile main body 2 includes a web portion 21, a pair of flange portions 22, and a pair of joint portions 24. The steel sheet pile main body 2 is formed such that a pair of flange portions 22 are continuously inclined at both ends of the web portion 21, and a pair of joint portions 24 are continuous to one end of each of the pair of flange portions 22. Formed.

  In the second embodiment, the closed steel material 3 is formed to have a substantially U-shaped cross-sectional shape. The closed steel material 3 is formed by cutting a U-shaped steel sheet pile or the like, and has a closed web portion 31, a pair of closed flange portions 32, and a pair of closed joint portions 34. The closed steel material 3 is formed such that a pair of closing flange portions 32 are continuously inclined at both ends of the closing web portion 31, and a pair of closing joint portions 34 is provided at one end of each of the pair of closing flange portions 32. It is formed continuously. The closed steel material 3 is joined to the distal end portion 2a of the steel sheet pile main body 2 by bringing each closed joint portion 34 and each joint portion 24 of the steel sheet pile main body 2 into contact with each other and performing welding joint or the like. .

  As shown in FIG. 4 (a), the steel sheet pile main body 2 to which the present invention is applied is provided with a steel sheet pile main body 2 on a tip portion 2 a provided on a support layer 8 a of the ground 8 and on a surface layer 8 c of the ground 8. A plurality of water jet pipes 5 are provided so as to be continuous from the base end 2b of the steel sheet pile main body 2 to the front end 2a. In the water jet pipe 5, the base end 2 b side of the steel sheet pile main body 2 is connected to the water feed pump, and the nozzle 5 a is provided on the tip end 2 a side of the steel sheet pile main body 2.

  As shown in FIG. 4 (b), the front-end processed steel sheet pile 1 to which the present invention is applied is opened in the steel sheet pile main body 2 toward the side in the cross-sectional direction X by the web portion 21 and the pair of flange portions 22. An open cross section 20 is formed. In the tip processed steel sheet pile 1 to which the present invention is applied, the closed steel material 3 is joined to the steel sheet pile main body 2 as shown in FIG. 4 (c) so as to close the open section 20 formed in the steel sheet pile main body 2. The

  As shown in FIG. 4, the tip-processed steel sheet pile 1 to which the present invention is applied has an open section 20 that opens toward the side in the cross-sectional direction X, which is closed by the closed steel material 3, and the tip portion 2 a of the steel sheet pile main body 2. Thus, the tip processed portion 4 is formed. The front end processed portion 4 is a cross-sectional view with respect to the longitudinal direction Y of the steel sheet pile main body 2, and the closed steel material 3 is joined to the steel sheet pile main body 2, and the open cross section 20 opened toward the side in the cross sectional direction X is the closed steel material. 3, a closed cross section 25 is formed by the steel sheet pile main body 2 and the closed steel material 3.

  As shown in FIG. 5, the tip processing portion 4 is a cross-sectional view with respect to the longitudinal direction Y of the steel sheet pile main body 2, and a pair of closing arm portions 33 of the closed steel material 3 and a pair of arm portions 23 of the steel sheet pile main body 2. Are brought into contact with each other, and a pair of joints S are formed, and a joint line N between the steel sheet pile main body 2 and the closed steel member 3 is assumed on a line connecting the pair of joints S. The tip processing portion 4 is formed so that the steel sheet pile main body 2 and the closed steel material 3 have substantially the same cross-sectional shape, so that the steel sheet pile with respect to the joining line N between the steel sheet pile main body 2 and the closed steel material 3. A closed cross section 25 having a predetermined cross-sectional area Ap is formed so that the main body side A on which the main body 2 is provided and the processing side B on which the closed steel material 3 is provided are substantially line symmetric.

  The tip processing part 4 is an outer side of a closed section 25 formed by the steel sheet pile main body 2 and the closed steel material 3 on each of the main body side A on which the steel sheet pile main body 2 is provided and the processing side B on which the closed steel material 3 is provided. In addition, one water jet pipe 5 is attached. At this time, the tip processing unit 4 has a quantity of water jet pipes 5 attached to the main body side A where the steel sheet pile main body 2 is provided and a quantity of water jet pipes 5 attached to the processing side B where the closed steel material 3 is provided. Are substantially the same.

  The tip processing portion 4 is not limited to this, and one or a plurality of water jet pipes 5 are mounted on each of the main body side A on which the steel sheet pile main body 2 is provided and the processing side B on which the closed steel material 3 is provided, The number of water jet tubes 5 attached to the main body side A and the number of water jet tubes 5 attached to the processing side B may be substantially the same or different.

  The tip processing portion 4 is a main body side A on which the steel sheet pile main body 2 is provided, and the water jet pipe 5 is fixed to one flange portion 22 of the steel sheet pile main body 2 by welding and the processing side B on which the closed steel material 3 is provided. Thus, the water jet pipe 5 is fixed to the one closed flange portion 32 of the closed steel material 3 by welding. The tip processing part 4 is not limited to this, but each of the web part 21 of the steel sheet pile main body 2 and the closed web part 31 of the closed steel material 3, each of the arm part 23 of the steel sheet pile main body 2 and each of the closed arm part 33 of the closed steel material 3. Alternatively, the water jet pipe 5 may be attached to each of the boundary between the arm portion 23 and the flange portion 22 of the steel sheet pile main body 2 and the boundary between the closing arm portion 33 and the closing flange portion 32 of the closed steel material 3. Further, the water jet pipe 5 is not limited to this, and may be fixed by a mounting bracket or the like.

  The tip processing portion 4 is substantially point-symmetric with respect to the center point C of the closed cross section 25 formed by the steel sheet pile main body 2 and the closed steel material 3 in a cross sectional view with respect to the longitudinal direction Y of the steel sheet pile main body 2. The water jet pipe 5 is attached to one flange portion 22 of the steel sheet pile main body 2 on the main body side A where the steel sheet pile main body 2 is provided, and one side of the closed steel material 3 on the processing side B where the closed steel material 3 is provided. The water jet pipe 5 is attached to the closed flange portion 32.

  The tip processing portion 4 is non-symmetrical with respect to the joining line N between the steel sheet pile main body 2 and the closed steel material 3 on the main body side A where the steel sheet pile main body 2 is provided and the processing side B where the closed steel material 3 is provided. On the processing side B on which the water jet pipe 5 is attached only to one flange portion 22 of the steel sheet pile main body 2 and the closed steel material 3 is provided on the main body side A on which the steel sheet pile main body 2 is provided, The water jet pipe 5 is attached only to one closing flange portion 32 of the closing steel material 3.

  When the steel sheet pile main body 2 and the closed steel material 3 are propelled into the ground, the tip processing portion 4 is summed with the main body side ejection pressure P1 of the water jet pipe 5 attached to the main body side A on which the steel sheet pile main body 2 is provided. The jet pressure of the water jet pipe 5 is set so that the total sum of the processing jet pressure P2 of the water jet pipe 5 mounted on the processing side B on which the closed steel material 3 is provided is substantially the same. The tip processing portion 4 includes a quantity of water jet pipes 5 attached to the main body side A on which the steel sheet pile main body 2 is provided, and a quantity of water jet pipes 5 attached to the processing side B on which the closed steel material 3 is provided. Are set so that, for example, the ejection pressures of the water jet pipes 5 are substantially the same.

  As shown in FIGS. 6 to 10, the method for placing the tip processed steel sheet pile 1 to which the present invention is applied includes the tip processed steel sheet pile 1 having the steel sheet pile main body 2 and the closed steel material 3 as an intermediate layer 8 b in the ground. A propulsion step to be propelled by the step, and a support step to be supported by the support layer 8a in the ground as necessary.

  In the propulsion step, first, as shown in FIG. 6, the tip processed portion 4 of the tip processed steel sheet pile 1 is embedded from the surface layer 8 c of the ground 8 by a method such as striking, vibration, or press fitting. At this time, in the propulsion step, high-pressure water is ejected from the nozzle 5a of the water jet pipe 5, and the front-end processed portion of the front-end processed steel sheet pile 1 is stirred and fluidized with the high-pressure water. 4 will be promoted.

  Next, in the propulsion step, as shown in FIG. 7, the processing side on which the total steel body jet pressure P1 of the water jet pipe 5 attached to the main body side A on which the steel sheet pile main body 2 is provided and the closed steel material 3 is provided. The total of the processing-side jet pressure P2 of the water jet pipe 5 attached to B is substantially the same, and the intermediate layer 8b of the ground 8 is stirred and fluidized with high-pressure water, while being relatively soft in the ground. The steel sheet pile main body 2 is moved substantially straight at the intermediate layer 8b.

  Next, in the propulsion process, as shown in FIG. 8, the tip processing of the tip-worked steel sheet pile 1 at the intermediate layer 8b in the ground until reaching a depth of about 1 m above the relatively hard support layer 8a in the ground. After propelling the portion 4, the jet of high-pressure water from the nozzle 5a of the water jet pipe 5 is stopped so that the support layer 8a in the ground is not stirred and fluidized with high-pressure water. In the propulsion step, the depth is not limited to this, and any depth may be used to stop the ejection of high-pressure water from the nozzle 5a of the water jet pipe 5 in the support layer 8a or the intermediate layer 8b in the ground.

  In the supporting step, as shown in FIGS. 9 and 10, the tip processing portion 4 of the tip processing steel sheet pile 1 is made to penetrate into the support layer 8 a in the ground, thereby forming the steel sheet pile main body 2 and the closed steel material 3. The earth and sand 7 in the ground enters the closed section 25, and the earth and sand 7 entering the closed section 25 is compacted. At this time, in the supporting step, the closed cross-section 25 of the tip processing portion 4 is closed by the compacted earth and sand 7, whereby a high tip support force is applied to the tip portion 2a of the steel sheet pile main body 2. .

  The tip processed steel sheet pile 1 to which the present invention is applied, as shown in FIG. 9, has a joining extension L for joining the closed steel material 3 to the steel sheet pile main body 2 in the longitudinal direction Y of the steel sheet pile main body 2. The square root Dp (Dp = √Ap) of the cross-sectional area Ap of the four closed cross sections 25 can be set to about three times (L = 3 × Dp). At this time, as shown in FIG. 10 (a), the tip processed steel sheet pile 1 to which the present invention is applied has the entire joining extension L (L = 3 × Dp) of the tip processed portion 4 on the support layer 8a in the ground. Further, as shown in FIG. 10B, about 1/3 (L / 3 = Dp) of the joint extension L of the tip processed portion 4 may be embedded in the support layer 8a in the ground. Be good.

  The tip processed steel sheet pile 1 to which the present invention is applied, as shown in FIG. 11 (a), has a total of the main body side ejection pressure P1 of the water jet pipe 5 and a total of the processing side ejection pressure P2 of the water jet pipe 5. By making it substantially the same, it is assumed that the jet pressure of the water jet pipe 5 is balanced between the main body side A on which the steel sheet pile main body 2 is provided and the processing side B on which the closed steel material 3 is provided. The steel sheet pile main body 2 can be moved substantially straight by the intermediate layer 8b. On the other hand, in the conventional steel sheet pile 9, since the sum of the main body side ejection pressure P1 and the sum of the processing side ejection pressure P2 are not substantially the same, as shown in FIG. Therefore, the steel sheet pile 9 is inclined in the ground to the main body side A or the processing side B having a small ejection pressure.

  The tip processed steel sheet pile 1 to which the present invention is applied has a nozzle by balancing the jet pressure of the water jet pipe 5 between the main body side A where the steel sheet pile main body 2 is provided and the processed side B where the closed steel material 3 is provided. The ejection of the high-pressure water from 5a makes it possible to smoothly promote the tip processing portion 4 in the ground, and at the same time, the steel sheet pile main body 2 can be moved substantially straight in the ground and accurately propelled.

  The tip processed steel sheet pile 1 to which the present invention is applied includes a main body side A on which the steel sheet pile main body 2 is provided and a closed steel material with respect to a joining line N between the steel sheet pile main body 2 and the closed steel material 3 as shown in FIG. The closed cross section 25 is formed so as to be substantially line symmetric with the processing side B on which 3 is provided. Thereby, the tip processed steel sheet pile 1 to which the present invention is applied is the center point of the closed section 25 of the tip processed portion 4 between the main body side A where the steel sheet pile main body 2 is provided and the processing side B where the closed steel material 3 is provided. Since the mounting position of the water jet pipe 5 that is substantially equidistant from C is easily determined, the design accuracy of the mounting position of the water jet pipe 5 for making the steel sheet pile main body 2 to move substantially straight in the ground is improved. It becomes possible to make it.

  The tip processed steel sheet pile 1 to which the present invention is applied is substantially point-symmetric with respect to the center point C of the closed cross section 25 of the tip processed portion 4 and with respect to the joining line N between the steel sheet pile main body 2 and the closed steel material 3. One water jet pipe 5 is attached to each of the main body side A on which the steel sheet pile main body 2 is provided and the processing side B on which the closed steel material 3 is provided so as to be non-axisymmetric. At this time, the tip processed steel sheet pile 1 to which the present invention is applied can have up to two water jet pipes 5 attached to the tip processed portion 4.

  Moreover, the front-end processed steel sheet pile 1 to which the present invention is applied is substantially point-symmetric with respect to the center point C of the closed cross-section 25 of the front end processed portion 4 in a cross-sectional view with respect to the longitudinal direction Y of the steel sheet pile main body 2. As described above, at the main body side A where the steel sheet pile main body 2 is provided, the main body-side jet pressure P1 from the water jet pipe 5 acts in the G1 direction and the H1 direction, and at the processing side B where the closed steel material 3 is provided, The processing-side ejection pressure P2 from the jet pipe 5 acts in the G2 direction and the H2 direction. At this time, in the front-end processed steel sheet pile 1 to which the present invention is applied, the main body side ejection pressure P1 and the processing side ejection pressure P2 from the water jet pipe 5 act in substantially the same magnitude in the G1 direction and the G2 direction. At the same time, the H1 direction and the H2 direction act with substantially the same size.

  Thereby, the tip processed steel sheet pile 1 to which the present invention is applied suppresses an increase in the number of water jet tubes 5 by limiting the number of water jet tubes 5 attached to the tip processed portion 4 to two. Thus, it is possible to reduce the material cost and the installation cost of the water jet pipe 5. Moreover, the front-end processed steel sheet pile 1 to which the present invention is applied is a cross-sectional view with respect to the longitudinal direction Y of the steel sheet pile main body 2, and the main body side ejection pressure P1 and the processing side ejection pressure P2 from the water jet pipe 5 are changed to the G1 direction. And the G2 direction, the H1 direction, and the H2 direction are caused to cancel each other by acting in substantially the same size, and the jet pressure in the cross-sectional direction X from the water jet pipe 5 is balanced, Without making the steel sheet pile main body 2 tilt, the steel sheet pile main body 2 can be moved straightly accurately.

  As mentioned above, although the example of embodiment of this invention was demonstrated in detail, all the embodiment mentioned above showed only the example of actualization in implementing this invention, and these are the technical aspects of this invention. The range should not be construed as limiting.

1: tip processed steel sheet pile 2: steel sheet pile main body 2a: tip portion 2b: base end portion 20: open section 21: web section 22: flange section 23: arm section 24: joint section 25: closed section 3: closed steel 31: Closing web part 32: Closing flange part 33: Closing arm part 34: Closing joint part 4: Tip processing part 5: Water jet pipe 5a: Nozzle 7: Earth and sand 8: Ground 8a: Support layer 8b: Intermediate layer 8c: Surface layer A: Body side B: Processing side X: Cross-sectional direction Y: Longitudinal direction

Claims (3)

It is a tip-worked steel sheet pile with predetermined processing applied to the tip of the steel sheet pile,
A steel sheet pile main body having a web portion and a pair of flange portions formed continuously at both ends of the web portion, and a closed steel material provided at a longitudinal end portion of the steel sheet pile main body,
In the steel sheet pile main body, the closed steel material is joined so as to close an open cross section formed by the web portion and the pair of flange portions, and a tip processing portion is formed at a tip portion in the longitudinal direction. ,
The tip processing portion is substantially point-symmetric with respect to a center point of a closed cross section formed by the steel sheet pile main body and the closed steel material in a cross-sectional view with respect to the longitudinal direction of the steel sheet pile main body, and the steel sheet pile With respect to the joining line between the main body and the closed steel material, the water jet pipe is mounted so that the main body side where the steel sheet pile main body is provided and the processing side where the closed steel material is provided are axisymmetric. Advanced steel sheet pile characterized by The distal working portion, claims and quantity of the water jet tube which is mounted on the main body side, and quantity of the water jet tube which is mounted on the working side, characterized in that it is made of a same claim 1 Symbol placement of the tip processing sheet piles. It is a method for placing a tip processed steel sheet pile that has been subjected to predetermined processing on the tip of the steel sheet pile,
Providing a propulsion step of propelling a steel sheet pile main body having a web portion and a pair of flange portions and a closed steel material joined to a distal end portion in the longitudinal direction of the steel sheet pile main body in the ground,
In the propulsion step, the steel sheet pile main body is provided as the steel sheet pile main body substantially straight in the ground ,
In the steel sheet pile main body, the closed steel material is joined so as to close an open cross section formed by the web portion and the pair of flange portions, and a tip processing portion is formed at a tip portion in the longitudinal direction. ,
The tip processing portion is substantially point-symmetric with respect to a center point of a closed cross section formed by the steel sheet pile main body and the closed steel material in a cross-sectional view with respect to the longitudinal direction of the steel sheet pile main body, and the steel sheet pile With respect to the joining line between the main body and the closed steel material, the water jet pipe is mounted so that the main body side where the steel sheet pile main body is provided and the processing side where the closed steel material is provided are axisymmetric. A method for placing a tip-processed steel sheet pile characterized by the following:

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